
2-26
MPC603e & EC603e RISC Microprocessors User's Manual
MOTOROLA
2.3.4.2.1 Floating-Point Arithmetic Instructions
The floating-point arithmetic instructions are listed in Table 2-14. (Floating-point
instructions are not supported on the EC603e microprocessor.)
2.3.4.2.2 Floating-Point Multiply-Add Instructions
These instructions combine multiply and add operations without an intermediate rounding
operation. The fractional part of the intermediate product is 106 bits wide, and all 106 bits
take part in the add/subtract portion of the instruction.
The floating-point multiply-add instructions are listed in Table 2-15. (Floating-point
instructions are not supported on the EC603e microprocessor.)
Table 2-14. Floating-Point Arithmetic Instructions
Name
Mnemonic
Operand Syntax
Floating Add (Double-Precision)
fadd (fadd.)
fr
D
,fr
A
,fr
B
Floating Add Single
fadds (fadds.)
fr
D
,fr
A
,fr
B
Floating Subtract (Double-Precision)
fsub (fsub.)
fr
D
,fr
A
,fr
B
Floating Subtract Single
fsubs (fsubs.)
fr
D
,fr
A
,fr
B
Floating Multiply
(Double-Precision)
fmul (fmul.)
fr
D
,fr
A
,fr
C
Floating Multiply
Single
fmuls (fmuls.)
fr
D
,fr
A
,fr
C
Floating Divide (Double-Precision)
fdiv (fdiv.)
fr
D
,fr
A
,fr
B
Floating Divide Single
fdivs (fdivs.)
fr
D
,fr
A
,fr
B
Floating Reciprocal Estimate Single
fres (fres.)
fr
D
,fr
B
Floating Reciprocal Square Root Estimate
frsqrte (frsqrte.)
fr
D
,fr
B
Floating Select
fsel (fsel.)
fr
D
,fr
A
,fr
C
,fr
B
Table 2-15. Floating-Point Multiply-Add Instructions
Name
Mnemonic
Operand Syntax
Floating Multiply-Add (Double-Precision)
fmadd (fmadd.)
fr
D
,fr
A
,fr
C
,fr
B
Floating Multiply-Add Single
fmadds (fmadds.)
fr
D
,fr
A
,fr
C
,fr
B
Floating Multiply-Subtract (Double-Precision)
fmsub (fmsub.)
fr
D
,fr
A
,fr
C
,fr
B
Floating Multiply-Subtract Single
fmsubs (fmsubs.)
fr
D
,fr
A
,fr
C
,fr
B
Floating Negative Multiply-Add (Double-Precision)
fnmadd (fnmadd.)
fr
D
,fr
A
,fr
C
,fr
B
Floating Negative Multiply-Add Single
fnmadds (fnmadds.)
fr
D
,fr
A
,fr
C
,fr
B
Floating Negative Multiply-Subtract (Double-
Precision)
fnmsub (fnmsub.)
fr
D
,fr
A
,fr
C
,fr
B
Floating Negative Multiply-Subtract Single
fnmsubs (fnmsubs).
fr
D
,fr
A
,fr
C
,fr
B